/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/

let fnA = () => 'hello';
let fnB = () => 'lagou';
let fnC = () => 'I ♥ U';

Promise.all([fnA(), fnB(), fnC()]).then((res) => {
  let a = res.join('');
  console.log(a);
});
